The present invention relates to abrasion-resistant coke.
More particularly, the invention relates to a method of making abrasion-resistant coke, especially coke for use in adsorbing sulfur oxides from waste gases, and a rotary furnace for carrying out the method.
Industrial waste gases often contain sulfur oxides. These are ecologically harmful and should not be emitted into the atmosphere. Such emission can be avoided by removing the sulfur oxides from the gases prior to venting of the same.
It has been proposed to effect the removal of the sulfur oxides by adsorbing them on shaped coke. Such coke is manufactured by mixing particulate, non-caking fresh or fossil fuel (having a particle size which is 100% below 1.0 mm, preferably below 0.1 mm) with about 15-35% by weight of a binder (such as bitumen, tar or pitch), forming shaped coke bodies from the resulting mixture, and outgassing these bodies at temperatures of about 700.degree.-900.degree. C. Non-coking fuels suited for this purpose include charcoal, oxycoal, oxycoke and peat coke.
The finished coke is then used in a desulfurizing installation in which it is first placed into an adsorber. After the coke has adsorbed all the sulfur oxides and sulfuric acid it can accept, it is transferred to a desorber where it is regenerated in preparation for a new adsorbing cycle.
During the transportation into and out of the adsorbers and desorbers the coke is subjected to a substantial amount of mechanical stress, especially abrasion. A problem encountered in this connection--and heretofore unsolved--is that the known coke does not have the requisite hardness to successfully withstand the abrasion. As a result, there is a substantial amount of coke loss due to abrasion; this, of course, considerably increases the operating expenses of the installation.